Combined try-square and protractor



(No Model.)

. F. E. ROBERTS.

COMBINED TRY SQUARE AND PROTRAGTOR. A No. 425,698.

. Patented Apr. 15,1890.

WIM/58858:

UNITED STATES PATENT OFFICE.'

FRANKLIN E. ROBERTS, OF FLINT, MICHIGAN.

COMBINED TRY-SQUARE AND PROTRACTOR.

SPECIFICATION forming part 0f Letters Patent NO. 425,698, dated April 15, 1890.

Application led'Augnst 2, 1889. Serial No. 319,541. (No model.)

To all whom it may concern: l

Be it known that I, FRANKLIN E. ROBERTS, of Flint, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in Combined Try- Squares and Protractors, of which the following is a specification, reference being had to the accompanying drawings, in which- Figure l is a perspective View of my improvement. Fig. 2 is a horizontal section on the line 2 2, Fig. l. Fig. 3 is a cross-section of the same on the line 3 3, Fig. l.

The object of the invention is to provide an instrument by which operators or workmen in the various trades or arts may readily determine various angles and lay out work.

The invention will be first described and then specifically claimed.

A represents the frame of the instrument, consisting in an outer section B, formed of two approximately triangular or quadrant-shaped wings b b at right angles to each other, and an inner section C, formed of two similar Wings c c. The edges D of the frame are straight and at right angles to each other and form the try-square, said edges being graduated on the outer faces of all four wings b b 'c c into inches and fractions thereof. The several wings may be provided with registering openings d, if desired, in order to lighten the instrument. The angular space between the ends e of the frame is provided witha lling and spacing piece E, held therein by screws f flush with the faces of the several Wings. This piece E spaces the two frame-sections B C. In the spaces thus formed are placed two quadrants F F, which are each provided with a curved slot g concentric with the curved edges m. Concentric with these slots g are formed three series of radial graduations hij, the graduations of the inner series each representing ten degrees of radiation, the second ive degrees each, and the outer or third two and one-half degrees each.

Theedges a of the wings l) b c c are curved to register With the curved edges of the quad rants, and the latter are each provided with a thumb or finger projection n, by which they may be moved in or out.

G are setscrews passing through the trysquare portions of the frame A. and the slots g, the heads of the screws being nicked and .countersunln so as to be flush with the frame.

It willbe seen from the above that the quadrants may be moved wholly within the frame in order that the straight edges D thereof may be used as a try-square, and that by pressing the finger projection n outward any one of the radial graduations may be brought into line with the straight edge, when an angle may be marked on the work. By tightening the screw the quadrant will be firmly clamped between the two wings.

The instrument may be placed in the angle of a box or room when it is necessary to find out what such an angle may be, and if it is found to be greater than a right angle a quadrant may be moved outwardly and the exact angle determined.

The instrument is capable of many and varied uses by carpenters, millwrights, cabinetmakers, car-builders, and draftsmen, and it may be made of sheet or other metal, wood, or compressed pulp.

In practice I have found that it is not essential to place gures or other marks upon the quadrant graduators; but in some instances I propose to do so, and they may of course be varied indefinitely.

Having thus described my invention,what I claim, and desire to secure by Letters Patent, 1s

l. A combined try-square and protractor consisting in a try-square having separate and independent quadrants movably secured to its two members and adapted to be proj ected beyond the edges thereof, substantially as set forth. A

2. A combined try-square and protractor consisting in a try-square and quadrants provided with concentric slots and set-screws for clamping the quadrants in any desired position on the members of the trysquare, subh stantially as set forth.

A combined try-square and protractor consisting in a try-square having quadrants adjustably secured to its members and each provided with concentric series of radial graduations, substantially as set forth.

4. A combined trysquare and protractor consisting in a frame formed of inner and outer spaced sections," each formed of two .t wings at right angles to each otherto form thetry-square, and a protractor adjustable between each pair of wings, substantially as set forth.

5. A combined try-square and protractor consisting in a frame formed of inner and outer spaced sections, each having two wings at right angles to each other registering at their straight edges and forming the trysquare, the quadrants in the spaces between said wings, and set-screws for clamping the quadrants in their adjusted positions, substantially as set forth. f

' 6. A combined try-square and quadrant consisting in a frame formed of inner and outer spaced sections, each having two quadrant-shaped wings at right angles to each other with their straight edgesregistering, the quadrants in the spaces between the said Wings, and having finger projections on their curved edges projecting beyond the curved edges of the wings, substantially as described.

7. A combined square and quadrant consisting in a frame formed of separate and independent inner and outer sections, each having two wings at right angles .to each other registering at their straight edges, an angular spacing-piece between the two sections, 

